JP5430143B2 - Substrate manufacturing method - Google Patents

Description

  The present invention relates to a method for manufacturing a substrate.

  Conventionally, when manufacturing a semiconductor substrate including a solar cell element, etc., an ingot is cut into a predetermined size into a block shape, and after the block is bonded to a slice base with an adhesive, a wire saw device or the like is used. The substrate was manufactured by cutting into a plurality of sheets.

  In order to obtain a substrate with good thickness accuracy, for example, Japanese Patent Laid-Open No. 2004-133830 discloses a workpiece feed rate (feed rate) at the initial cutting as 1. A method of 5 to 4 times is described.

Note that, as a management of the substrate thickness, it has been common to manage the substrate thickness by measuring several points 10 mm or more inside from the edge of the substrate.
JP-A-6-155278

  In recent years, a substrate used for a solar cell has been reduced in thickness, and a wire having a small wire diameter is used in order to reduce kerf loss (cutting allowance). At this time, there was a problem that the thickness accuracy of the substrate was poor as shown in FIG. In particular, when the thickness of the end portion of the substrate is different from the average thickness of the entire substrate, there is a problem that cracks, cracks, and the like occur in the manufacturing process of the solar cell element, thereby reducing the yield.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a method for manufacturing a substrate with improved thickness accuracy of the substrate.

The substrate manufacturing method of the present invention includes a step of preparing a rectangular block having a plane and a substantially rectangular cross-sectional shape, and a wire traveling at a first speed toward the plane of the block. And a step of cutting a central portion of the block cut at the first speed by a wire traveling at a second speed higher than the first speed.

  According to the present invention, a solar cell element with reduced substrate thickness variation can be manufactured with the above-described configuration. In particular, the thickness of the end portion (cutting start portion) of the substrate is substantially the same as the average thickness of the entire substrate, and the yield is not easily lowered due to the occurrence of cracks or cracks in the element process of the solar cell element.

  Hereinafter, a method for manufacturing a substrate according to an embodiment of the present invention will be described in detail with reference to the drawings.

(First embodiment)
The substrate manufacturing method of the present embodiment includes a step of preparing a block having a plane, a step of advancing a wire that travels at a first speed to the plane of the block, and a step of starting cutting the block, and a speed higher than the first speed. Cutting the central portion of the block cut at the first speed with the wire traveling at the second speed.

  The block is formed by cutting the end of the ingot. Such an ingot is made of, for example, single crystal silicon or polycrystalline silicon. For example, when a single crystal silicon ingot is used, the single crystal silicon ingot has a cylindrical shape. Therefore, by cutting four side surfaces along the height direction, the cross-sectional shape is substantially rectangular (including a square). The silicon block can be obtained. In addition, what has a corner | angular part in circular shape in the said cross-sectional shape shall also be considered as a rectangle. The polycrystalline silicon ingot is generally a substantially rectangular parallelepiped and has a size that allows a plurality of silicon blocks to be taken out. The silicon block has a rectangular cross section (including a square), for example, 156 × 156. A 300 mm rectangular parallelepiped is formed. In addition, what the corner | angular part was chamfered in the said cross-sectional shape shall be considered as a rectangle.

  FIG. 1 is a perspective view showing a wire saw apparatus used in the substrate manufacturing method according to the present embodiment. In the configuration shown in FIG. 1, the traveling wire 3 and the square block 1 fixed to the slice base 2 are pressed against each other, and the block 1 is cut by the wire 3 to manufacture a substrate.

  The block 1 is bonded to a slice base 2 made of a material such as a carbon material, glass, resin or the like by an adhesive or the like. The adhesive is made of an adhesive such as a thermosetting two-component epoxy type, an acrylic type, a reacrate type, or a wax, and the temperature is raised so that the substrate 1a can be easily separated from the slice base 2 after slicing. Thus, an adhesive whose adhesive strength is reduced is used.

  Then, one or a plurality of semiconductor blocks 1 bonded to the slice base 2 are arranged in the apparatus by a work holder.

  In the first embodiment, a loose abrasive type wire saw device that cuts the block 1 by the lapping action of the wire 3 by supplying a cutting fluid containing abrasive grains is used.

  The wire 3 to be used is wound around the main roller 5, for example, a piano wire mainly composed of iron or an iron alloy may be used, and the wire diameter is 100 μm to 180 μm, more preferably 140 μm or less.

  The cutting fluid is configured by mixing lapping oil composed of abrasive grains such as silicon carbide, alumina, and diamond, mineral oil, a surfactant and a dispersant, and stretched to a plurality of nozzles from a supply nozzle 4 having a plurality of openings. Cutting fluid is supplied to the formed wire 3. As the average particle size of the abrasive grains, for example, those having a narrow particle size distribution of 5 μm to 20 μm are used. The supply flow rate of the cutting fluid supplied to the supply nozzle 4 is appropriately set depending on the size and number of blocks. Further, the cutting fluid may be circulated and used, and new abrasive grains may be additionally supplied at that time.

  The main roller 5 is made of, for example, a resin such as ester-based, ether-based / urea-based urethane rubber, or neurite, and has a diameter of about 150 to 500 mm and a length of about 200 to 1000 mm. The surface of the main roller 5 is provided with a number of grooves for arranging the wires 3 supplied from the wire supply reel 7 at predetermined intervals. The thickness of the substrate is determined by the relationship between the interval between the grooves and the diameter of the wire 3.

  The dip tank 6 is provided for the purpose of collecting block scraps and cutting fluid generated during cutting.

Below, the slicing method using a wire saw apparatus is demonstrated.
(A) First, the wires 3 and the blocks 1 provided in a plurality of rows are prepared.
(B) Next, the wire 3 traveling at the first speed toward the plane 1 s of the block 1 is advanced, and the cutting of the block 1 is started.
(C) Thereafter, the central portion of the block 1 cut at the first speed is cut by the wire 3 traveling at the second speed higher than the first speed.

The step (a) will be described.
The wires 3 are supplied from the wire supply reel 7 and are wound around the main roller 5 and arranged at predetermined intervals. When the main roller 5 is rotated at a predetermined rotation speed, the wire 3 can travel in the longitudinal direction of the wire 3. In the first embodiment, by causing the wire 3 to travel in one direction without reciprocating, the load on the motor that drives the main shaft that rotates the wire 3 can be reduced and the life of the apparatus can be extended.

The steps (a) to (c) will be described.
For cutting the block 1, the cutting fluid is supplied toward the wire 3 traveling from the supply nozzle 4 provided in the vicinity of the cutting portion, and the block 1 is lowered to approach the wire 3 so that the wire 3 This is done by relatively pressing the plane 1s. The block 1 is divided into a plurality of substrates 1a having a thickness of 200 μm or less, for example. At this time, the tension of the wire 3, the speed at which the wire 3 travels (travel speed), and the speed at which the block is lowered (feed speed) are appropriately controlled.

  In this embodiment, since the cutting fluid supplied to the wire 3 is supplied to the block in one direction by running the wire 3 in one direction using a loose abrasive type wire saw device, the cutting fluid is a substrate. Slicing into the inside stably, reducing the variation in the thickness of the substrate 1a after slicing, and slicing in which the disconnection of the wire 3 is reduced becomes possible.

  At the same time as slicing the block 1, the slice base 2 is also cut by about 2 to 5 mm, and the substrate 1 a is put into the next cleaning step while being bonded to the slice base 2.

  In the washing process, sludge and the like adhering at the time of slicing are first removed by washing with kerosene. After that, wipe the oil with an alkaline detergent, and then wash away the detergent with water. Then, the surface of the substrate 1a is completely dried by hot air or air and peeled off from the slice base 2 to complete the substrate 1a.

  In the method for manufacturing the substrate 1a in the present embodiment, the traveling speed of the wire 3 is slower at the initial cutting (first speed) than at the cutting of the central portion of the block 1 (second speed). Here, the second speed refers to the speed of the wire 3 in a steady state when the central portion is cut. By making such a slicing condition, as shown in FIG. 2, it is difficult to alternately form a thick substrate and a thin substrate at the beginning of cutting, and the thickness of the edge at the beginning of cutting becomes the entire substrate. The thickness can be controlled to be approximately the same as the average thickness.

  The thickness of the substrate 1a can be measured using a contact-type or non-contact-type thickness measuring device. In particular, when measuring the thickness in the range from the end of the substrate 1a to 10 mm, it is preferable to use a non-contact type thickness measuring apparatus. The total average thickness of the substrate 1a was determined by measuring the thickness of a total of five points consisting of four B points each 15 mm away from the center A point shown in FIG. For the thickness of the first cut end, the thickness at point C 2 to 5 mm away from the substrate end was measured.

  Further, by changing the traveling speed of the wire 3 and reducing the supply flow rate of the cutting fluid at the initial cutting time (at the start of cutting) rather than at the time of cutting the central portion, the cutting start end portion (cutting start portion) ) Can be controlled to a thickness that is substantially the same as the average thickness of the entire substrate, and variations in the thickness of the entire substrate can be suppressed.

  Furthermore, while changing the traveling speed of the wire 3, the feed speed at which the block 1 is moved toward the wire 3 is also made slower at the initial cutting time than at the cutting of the central portion, so that the wire 3 is disconnected. Can be reduced, and variations in the thickness of the entire substrate can be suppressed.

  The running speed, supply flow rate, and feed speed at the time of initial cutting mean the minimum speed and the minimum flow rate when cutting from the end surface 1s of the block 1 facing the wire 3 to a depth of 1 mm. The traveling speed, supply flow rate, and feed speed for cutting the central portion of 1 are the speed and flow rate when cutting in a steady state. The cutting start end face 1s of the block 1 is set to 0, and the cutting end face is set to 1. In this case, the average speed and the average flow rate when cutting 1/3 to 2/3 are meant.

  Further, as shown in FIGS. 4A and 4B, the load on the wire 3 can be reduced by increasing the traveling speed of the wire stepwise or continuously from the initial cutting. The problem that the wire 3 is disconnected can be suppressed.

  Furthermore, the thickness variation of the entire substrate is increased by increasing the cutting fluid supply flow rate and / or the feed speed of the block 1 stepwise or continuously from the initial cutting time in accordance with the change in the traveling speed of the wire 3. Can be suppressed. Here, stepwise means that the speed or flow rate is maintained at a certain value for a certain period of time and then changed, and continuous means that the speed or flow rate is maintained at a certain value for a certain period of time without change. I mean.

  Further, the running speed of the wire 3 is set to the running speed at the time of cutting the central portion within a depth range of 2 mm to 50 mm, more preferably 5 to 20 mm from the cutting start end face 1 s of the block, so that the end of the cutting start Can be controlled to be substantially the same as the average thickness of the entire substrate.

  Further, the flow rate of the cutting fluid and / or the feed speed of the block is also centered in the depth range of 2 mm to 50 mm, more preferably 5 to 20 mm from the block cutting start end face 1 s in accordance with the change in the wire traveling speed. By making the supply flow rate and feed speed at the time of cutting a part, the thickness of the edge at the beginning of cutting can be managed to be almost the same as the average thickness of the whole substrate, and the cutting time can be improved and the time taken for slicing can be suppressed. it can.

  The first speed of the wire 3 is, for example, 200 m / min or more and 500 m / min or less, and the second speed is 600 m / min or more and 1000 m / min or less.

  Moreover, in the supply flow rate of the cutting fluid, the supply flow rate at the initial cutting is 60% or more and 80% or less of the supply flow rate at the cutting of the central portion. The supply flow rate of the cutting fluid varies depending on the size and number of blocks. For example, when slicing two blocks 1 having a length of 300 mm, 80 L / min or more and 150 L / min when cutting the central portion of the block 1. Used in the following.

  Further, in the feed speed of the block 1, the feed speed at the initial cutting is 30% or more and 60% or less of the feed speed at the cutting of the central portion. Although the feed speed of the block differs depending on the size and number of the blocks, for example, when slicing two blocks of 300 mm in length, they are used at 220 μm / min or more and 500 μm / min or less when cutting the central portion.

  Further, as shown in FIG. 5A, the traveling speed of the wire 3 and the supply flow rate of the cutting fluid are in a steady state in the cutting process. In FIG. 5A, the timing at which the traveling speed of the wire 3 is in a steady state is slower or the same as the timing at which the cutting fluid supply flow rate is in a steady state. The depth (cutting position) X at which the block 1 is cut before the first speed of the wire 3 reaches the second speed is the block 1 from when the cutting fluid supply flow rate reaches the steady state from the start of cutting. Is deeper than or equal to the cut depth (cutting position) Y. That is, it means that the supply flow rate of the cutting fluid is faster than the traveling speed of the wire 3 or increases to the value of the central portion at the same timing. By controlling the slicing condition within the above range, the block 1 can be sliced without degrading the machinability and without placing a burden on the wire 3.

  Furthermore, as shown in FIG. 5B, the traveling speed of the wire 3 and the feed speed of the block 1 are in a steady state in the cutting process. In FIG. 5A, the timing at which the traveling speed of the wire 3 is in a steady state is earlier or the same as the timing at which the feed speed of the silicon block 1 is in a steady state. Here, the speed of the wire 3 in a steady state (when the center portion is cut) is referred to as a second speed. The depth (cutting position) X at which the block 1 is cut before the first speed of the wire 3 becomes the second speed is equal to the block 1 until the feed speed of the block 1 reaches the steady state from the start of cutting. Is made shallower than or equal to the cut depth (cutting position) Z. That is, it means that the traveling speed of the wire 3 is faster than the feed speed of the block 1 or increases to the value of the central portion at the same timing. By controlling the slicing condition within the above range, the block 1 can be sliced without degrading the machinability and without placing a burden on the wire 3. Note that there is no consistency between the travel speed value and the feed speed value on the vertical axis of FIG. 5B, and the travel speed is actually much higher than the feed speed.

(Second embodiment)
Next, a difference between the second embodiment and the first embodiment will be described. In the second embodiment, a fixed abrasive type wire saw device is used that cuts with an abrasive fixed wire in which abrasive particles are fixed to the wire from the beginning.

  The wire 3 in this embodiment consists of a piano wire which has iron or an iron alloy as a main component, for example, and a wire diameter is 80 micrometers-180 micrometers, More preferably, it is 120 micrometers or less. The wire 3 has diamond or silicon carbide abrasive grains fixed around it by plating with nickel, copper or chromium. The average grain size of the abrasive grains is preferably 5 μm or more and 30 μm or less.

  And coolant liquid is used instead of cutting fluid, and coolant liquid consists of water-soluble solvents, such as glycol, for example, and is supplied to a plurality of wires 3 from an opening of supply nozzle 4 which has a plurality of openings. Is done.

Below, the slicing method using the wire saw apparatus of this embodiment is demonstrated.
(A) First, the wires 3 and the blocks 1 provided in a plurality of rows are prepared.
(B) Next, the wire 3 traveling at the first speed toward the plane 1 s of the block 1 is advanced, and the cutting of the block 1 is started.
(C) Thereafter, the central portion of the block 1 cut at the first speed is cut by the wire 3 traveling at the second speed higher than the first speed.

The step (a) will be described.
In the second embodiment, by causing the wire 3 to reciprocate, the abrasive grains fixed to the wire 3 can be used effectively and productivity can be improved.

The steps (a) to (c) will be described.
The block 1 is cut while the coolant liquid is supplied toward the wire 3 running from the supply nozzle 4 provided in the vicinity of the cutting portion, the block 1 is lowered and brought close to the wire 3, and the wire 3 is connected to the wire 3. This is done by relatively pressing the plane 1s. The block 1 is divided into a plurality of substrates 1a having a thickness of 200 μm or less, for example.

  Also in the manufacturing method of the board | substrate 1a in this embodiment, the traveling speed of the wire 3 is slower at the time of initial cutting (1st speed) than the time of cutting of the center part of the block 1 (2nd speed). By making such a slicing condition, as shown in FIG. 2, it is difficult to alternately form a thick substrate and a thin substrate at the beginning of cutting, and the thickness of the edge at the beginning of cutting becomes the entire substrate. The thickness can be controlled to be approximately the same as the average thickness. The wire 3 of the present embodiment travels in one direction at a steady speed, then decelerates and stops temporarily, accelerates in the reverse direction to reach a steady speed, then decelerates and stops, and travels in the opposite direction again. Do (round trip). For this reason, the traveling speed here means a steady speed.

  Furthermore, while changing the traveling speed of the wire 3, the feed speed of the block 1 is also made slower at the initial cutting time than at the cutting of the central portion, thereby reducing problems such as the disconnection of the wire 3 and the board. Overall thickness variation can be suppressed. Also, the feed speed is adjusted according to the traveling speed of the reciprocating wire 3 described above, that is, the feed speed is slowed when the traveling speed of the wire 3 is slow, and the feed speed is fast when the traveling speed is fast. May be made to be faster. Therefore, the feed speed in the case where the speed adjustment is performed means a steady speed.

  In addition, the burden on the wire 3 can be reduced by increasing the feed speed stepwise or continuously from the initial cutting according to changes in the wire traveling speed or the wire 3 traveling speed. The problem that the wire 3 is disconnected can be reduced.

  Further, the feed speed is cut at the central portion within a depth range of 2 mm to 50 mm, more preferably 5 to 20 mm from the cutting end face 1 s of the block in accordance with changes in the traveling speed of the wire 3 and the traveling speed of the wire 3. By setting the running speed or the feed speed at the time, the thickness of the end portion at the start of cutting can be managed to be approximately the same as the average thickness of the entire substrate.

  The first speed of the wire 3 is, for example, 350 m / min or more and 500 m / min or less, and the second speed is 600 m / min or more and 1000 m / min or less.

  Further, in the feed speed of the block 1, the feed speed at the initial cutting is 40% or more and 80% or less of the feed speed at the cutting of the central portion. Although the feed speed of the block varies depending on the size and number of blocks, for example, when slicing two blocks of 300 mm in length, they are used at 350 μm / min or more and 1100 μm / min or less when cutting the central portion.

  Thus, since the substrate 1a formed by the above-described manufacturing method can manage the thickness of the substrate end portion, in the element process of the solar cell element, the generation of cracks and cracks is prevented, and the solar cell element with high yield Can be produced.

  In addition, this invention is not limited to the said embodiment, Many corrections and changes can be added within the scope of the present invention.

  For example, the slicing process may be performed as it is without cutting the ingot 1.

Example 1
Examples will be described below.

  First, an epoxy adhesive was applied to a slice base made of a glass plate, and a rectangular parallelepiped polycrystalline silicon block of 156 mm × 156 mm × 300 mm was placed on the slice base to cure the adhesive. As shown in FIG. 1, a silicon block bonded to two slice bases is installed in a wire saw device, and a cutting fluid comprising silicon carbide abrasive grains (# 1200), mineral oil, a surfactant, and a dispersant is added. While supplying the wire (wire diameter of 120 μm) running in one direction, the block adhered to the slice base was sliced to produce a silicon substrate having an average thickness of 200 μm. The slicing conditions are as follows: the wire traveling speed at the time of initial cutting is 8 conditions of 150 m / min, 180 m / min, 200 m / min, 300 m / min, 350 m / min, 400 m / min, 500 m / min, 600 m / min, cutting The liquid supply flow rate is 120 L / min, the feed speed of the silicon block is 150 μm / min, the wire travel speed when cutting the central part is 700 m / min, the cutting fluid supply flow rate is 120 L / min, and the silicon block feed speed is It was set to 270 μm / min. In addition, each value was continuously enlarged so that it may become the conditions at the time of cutting | disconnection of a center part, when it cuts 10 mm from the cutting start edge part.

  Moreover, the slice conditions of the comparative example were a wire traveling speed of 700 m / min, a cutting fluid supply flow rate of 120 L / min, and a silicon block feed speed of 270 μm / min.

The average thickness of the silicon substrate obtained in each condition and the thickness of the first cut edge were measured, and the difference was evaluated as an absolute value. The difference in thickness is an average value when 500 sheets are measured. Moreover, the wire breakage rate under each condition was also confirmed. The disconnection rate was evaluated as a percentage of the number of disconnections when slicing was performed 50 times.
The results are shown in Table 1.

  As shown in Table 1, the difference between the average thickness of the substrate and the thickness at the beginning of cutting can be reduced by making the wire traveling speed at the time of initial cutting slower than the condition at the time of cutting the central portion. confirmed. In the comparative example, a substrate with a thick end and a thin substrate were alternately formed by visual confirmation. In 1-8, it has confirmed that the said problem was suppressed by making the traveling speed of the wire at the time of initial cutting slow. In particular, when the thickness is 500 mm / min or less, the difference in thickness can be more effectively suppressed, and when the thickness is 200 mm / min or more, the wire can be sliced without disconnection.

(Example 2)
Next, the slicing of the silicon block was performed under the conditions described below as part of the slicing conditions of Example 1. Regarding the slicing conditions, the wire traveling speed at the time of initial cutting was 350 m / min, the cutting fluid supply flow rate was 60 L / min, 72 L / min, 80 L / min, 90 L / min, 96 L / min, and 110 L / min. Condition.

The average thickness of the silicon substrate obtained in each condition and the thickness of the first cut edge were measured, and the difference was evaluated as an absolute value. Moreover, the wire breakage rate under each condition was also confirmed.
The results are shown in Table 2.

  No. No. 5, results and No. From the results of 9 to 14, it was confirmed that the difference between the average thickness of the substrate and the thickness at the beginning of the cutting is reduced by making the supply flow rate of the cutting fluid smaller than the condition at the time of cutting the central portion. In particular, when the cutting fluid supply flow rate at the initial cutting is 96 L / min or less, that is, the supply flow rate at the initial cutting is 80% or less of the supply flow rate at the cutting of the central portion, the thickness can be more effectively increased. The difference can be suppressed, and more than 72 L / min, that is, the supply flow rate at the time of initial cutting is set to 60% or more of the supply flow rate at the time of cutting the central portion, so that the wire can be sliced without disconnection. did it.

(Example 3)
First, an epoxy adhesive was applied to a slice base made of carbon, and a 156 mm × 156 mm × 300 mm rectangular polycrystalline silicon block was placed on the slice base to cure the adhesive. As shown in FIG. 1, a silicon block bonded to two slice bases is installed in a wire saw apparatus, and diamond abrasive grains (average particle diameter 10 μm) traveling in both directions with a coolant liquid made of glycol are provided. While supplying to the fixed wire (wire diameter 120 μm), the block bonded to the slice base was sliced to produce a silicon substrate having an average thickness of 200 μm. The slicing conditions are as follows: the wire traveling speed at the time of initial cutting is 300 m / min, 350 m / min, 400 m / min, 450 m / min, 500 m / min, 550 m / min, 600 m / min, 700 m / min, silicon The feed speed of the block was set to 300 μm / min, the running speed of the wire when cutting the central portion was set to 800 m / min, and the feed speed of the silicon block was set to 500 μm / min. In addition, each value was continuously enlarged so that it may become the conditions at the time of cutting | disconnection of a center part, when it cuts 10 mm from the cutting start edge part.

  In addition, the slicing conditions of the comparative example were a wire traveling speed of 800 m / min, a cutting fluid supply flow rate of 120 L / min, and a silicon block feed speed of 500 μm / min.

The average thickness of the silicon substrate obtained in each condition and the thickness of the first cut edge were measured, and the difference was evaluated as an absolute value. The difference in thickness is an average value when 500 sheets are measured. Moreover, it confirmed also about the defect rate of the saw mark with which the trace of a wire remains on the board | substrate in each conditions.
The results are shown in Table 3.

  As shown in Table 1, the difference between the average thickness of the substrate and the thickness at the beginning of cutting can be reduced by making the wire traveling speed at the time of initial cutting slower than the condition at the time of cutting the central portion. confirmed. In the comparative example, a substrate with a thick end and a thin substrate were alternately formed by visual confirmation. In 15-22, it has confirmed that the said problem was suppressed by slowing down the traveling speed of the wire at the time of initial cutting | disconnection. In particular, by setting the thickness to 350 mm / min or more and 500 mm / min or less, it was possible to more effectively suppress the difference in thickness, and it was possible to slice while suppressing the defect of the saw mark.

It is the schematic which shows one Embodiment of the wire saw apparatus in the manufacturing method of the board | substrate of this invention. It is an enlarged view which shows one Embodiment of the cutting start edge part in the manufacturing method of the board | substrate of this invention. It is the figure which showed the place which measures the thickness of a board | substrate. (A), (b) is a figure which shows one Embodiment of the time-dependent change of the wire travel speed in the manufacturing method of a board | substrate. (A) is a figure which shows the time-dependent change of the wire travel speed in the board | substrate manufacturing method, and the supply flow rate of a cutting fluid, (b) is one implementation of the time-dependent change of the wire travel speed and the block feed speed in the board | substrate manufacturing method. It is a figure which shows a form. It is an enlarged view of the cutting start edge part in the manufacturing method of the conventional board | substrate.

Explanation of symbols

1: Block 1a: Substrate 1s: Plane plane 3: Wire

Claims (13)

A step to have a flat sectional shape is prepared substantially rectangular prismatic block,
Advancing a wire traveling at a first speed toward the plane of the block and starting cutting the block;
Cutting a central portion of the block cut at the first speed with a wire traveling at a second speed higher than the first speed;
The manufacturing method of the board | substrate which has this.   The cutting of the block is performed by supplying cutting fluid containing abrasive grains, and the supply flow rate of the cutting fluid is smaller at the start of cutting than when cutting the central portion of the block. The manufacturing method of the board | substrate of Claim 1. 3. The substrate according to claim 1, wherein a feed speed for moving the block toward the wire is slower at the start of cutting than at the time of cutting the central portion of the block. Production method. The substrate manufacturing method according to any one of claims 1 to 3 , wherein the traveling speed of the wire is increased stepwise or continuously from the start of cutting. A method for manufacturing a substrate according to any one of claims 2-4, characterized in that to increase stepwise or continuously the supply flow rate of the cutting fluid from the time of the cutting start. A method for manufacturing a substrate according to any one of claims 3-5, characterized in that to increase stepwise or continuously feed speed of the block from the time of the cutting start. The running speed of the wire, to any one of claims 1 to 6, characterized in that the transition from the first speed in the depth range 2mm or less than 50mm from said plane of said block to said second speed The manufacturing method of the board | substrate of description. Wherein the first rate, the substrate manufacturing method according to any one of claims 1 to 7, characterized in that at 200 meters / min or more 500 meters / min or less. Said second rate, the substrate manufacturing method according to any one of claims 1 to 8, characterized in that at 600 meters / min or more 1000 m / min or less. The supply flow rate of the cutting start the cutting fluid is according to any one of claims 2-9, characterized in that said central portion is 80% to 60% or more of the supply flow rate of the cutting fluid during disconnection of the following Substrate manufacturing method. The method for manufacturing a substrate according to any one of claims 3 to 10 , wherein a feed speed of the block at the start of the cutting is 30% or more and 60% or less of a feed speed at the time of cutting the central portion. . The depth at which the block is cut before the first speed of the wire reaches the second speed is determined by the cutting of the block until the cutting fluid supply flow rate reaches a steady state from the start of cutting. The method for manufacturing a substrate according to any one of claims 2 to 11 , wherein the substrate is deeper than or equal to the set depth. The depth at which the block is cut before the first speed of the wire reaches the second speed is determined so that the block is cut until the feed speed of the block reaches a steady state from the start of cutting. The method for manufacturing a substrate according to any one of claims 3 to 12 , wherein the substrate is shallower than or equal to the depth.

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